[[#|Major depression]] is when a person has five or more [[#|symptoms of depression]] for at least 2 weeks. These symptoms include feeling sad, hopeless, worthless, or pessimistic. In addition, people with [[#|major depression]] often have behavior changes, such as new eating and sleeping patterns. Another major characteristic of the disorder is thoughts death or suicide. With or without therapy episodes of major depression normally end. Some people temporarily or permanently return to their previous behavior patterns. However, some rebound and experience an extreme emotional opposite, also known as the euphoric, hyperactive and wildly optimistic state of mania. In other words if depression is a state of slow motion, mania is fast forward. Alternating between the two signals bipolar disorder. Some say depression feels like the anguish of grief mixed with the sluggishness associated with jet lag.
Source: Myers Text Book

Diagnosis: Major depression is diagnosed if a person reports having five or more [[#|depressive symptoms]] for at least 2 weeks. Beck's Depression Scale Inventory, the DSM-IV or other screening tests for depression can be helpful in making the diagnosis.Before diagnosing depression, the health care provider should rule out medical conditions that can cause [[#|symptoms of depression]].

Symptoms:

Agitation, restlessness, and irritability

Dramatic changes in appetite, often with weight gain or loss when not dieting

Inactivity and withdrawal from usual activities; a loss of interest or pleasure in activities that were once enjoyed

Thoughts of death or suicide, even suicide attempts

Trouble sleeping (insomnia) or excessive sleeping (hypersomnia)

Persistent feelings of sadness

Having low self-esteem and feeling of inadequacy

Difficulty with relationships and concentration

Physical ailments (ex. headache, stomach ache, fatigue)

Periods of hostility and aggression

Causes:The exact [[#|cause of depression]] is unknown. Many researchers believe it is caused by chemical imbalances in the brain, which may be hereditary or caused by events in a person's life. (stress-diathesis model; nature v. nurture)

Biological Factors: chemical imbalances in the brain. Three neurotrasmitters (chemical messengers in the brain which stimulate neuronal activity) have been found to be linked to depression: Serotonin, Norepinephrine, and Dopamine. Serotonin regulates mood and feelings of joy. A lack of serotonin, faulty receptors, or rapid reuptake of this molecule can [[#|cause depression]] by not allowing it to be transmitted from neuron to neuron, thereby preventing mood regulation.

Environmental and Genetic Factors: Some types of depression seem to run in families, but depression can also occur in people who have no family history of the illness. Stressful life changes or events can trigger depression in some people. Usually, a combination of factors is involved.Studies of identical twins have shown that if one twin has depression, the other twin has about a 1 in 2 chance of developing the disorder at some point during their life. Fraternal twins have a much lower correlation.

Gender Correlation: Men and women of all ages, races, and economic levels can have depression. It occurs more often in women. About ten percent of women suffer from this, as compared to around six percent of men. Women are especially vulnerable to depression after giving birth, called postpartum depression . This is a result of hormonal and physical changes.

Situational Factors: People may experience episodes of depression after surgery, fighting in a war, or during winter months (SAD: Seasonal Affective Disorder). Therapy and alternative treatments are often most effective in the treatment of these disorders. For example, light therapy is widey used for patients with SAD.

Treatments:Electro Convulsive Therapy, which induces a seizure through electrical currents. Some psychologists believe that this can improve the mood of those who are very depressed or suicidal, because it acts very quickly. (and is therefore the best option for some severely depressed patients). Another option is Trans-cranial Magnetic Simulation, which provides similar electric currents but it seems to have less adverse side effects. These treatments are generally only used after other treatments have failed to make a significant impact. From a biological standpoint, treatments include SSRI's (selective serotonin reuptake inhibitors) and SNRI's (serotonin and norepinephrine reuptake inhibitors) which cause the neurotransmitters to be present in the synapse for longer, giving them a greater chance of reaching the receptors of the post-synaptic neuron. However, for treatments to be effective the patient must maintain a healthy lifestyle with exercise, proper diets, and avoiding harmful things such as cigarettes or alcohol. Lifestyle changes are necessary in addition to any medical therapy for a lasting treatment of the disease.
Source: google.com/health

Helplessness Theories: Learned helplessness results from when a person is conditioned to behave helplessly. They believe in an external locus of control and feel that no matter what they do, they lack the ability to change things for themselves.

Cognitive Errors and Biases in Depression:

a) Black and white (all or nothing) thinking

b) Magnification/minimization

c) Arbitrary Inference

d) Overgeneralizaion

a) Taking an extreme view of a situation
Situation: getting an 1800 on the SAT
Thought: If I don't get a 2400 I'm the stupidest person alive

b) Exaggerating or ignoring a particular aspect of a situation
Situation: Marigold isn't invited to Lawrence Jr.'s party
Thought: He obviously hates me, I must be a terrible person.

c) Drawing negative conclusions when there is little information to support them.
Situation: Mom forgets to pick you up from school

d)A gross generalization based on one small event.
Situation: Someone fails a chemistry test
Thought: I'm never going to be a doctor now, I'm a failure at everything I try

Source: Abnormal Pyschology Volume 6

Please notice how she doesn't have this disease until after she has a life changing surgery. One major cause of this disease is because of a tramatic expierence or event.

Video: Boring, but good knowledge if you want to learn how the victim of the disease actually feels.

Seasonal Affective Disorder (SAD)

According to the DSM-IV, SAD is not considered a unique mood disorder but a specific form of Major Depressive Disorder. SAD causes in people that have normal mental health throughout the rest of the year to experience symptoms of depression in the late fall and winter months (there are rarer cases of SAD occurring in late spring through summer, where patients have heightened levels of anxiety). SAD is thought to be partly linked to a lack of vitamin D, which the body creates when exposed to sunlight. Thus is areas where winters are especially gray, SAD is found to be more common (for example, there is a prevalence of the disorder of 9.7% in New Hampshire compared to only 1.4% in Florida).

Symptoms include a lack of energy, difficulty waking up in the morning, oversleeping, an increased appetite which can result in weight gain, difficulty concentrating, and social withdrawal. In order to be diagnosed specifically with SAD, patients' behavior must meet four criteria: depressive episodes at a particular time of year; loss of these symptoms or episodes of mania/hypomania at a particular time of year; these seasonal episodes must have lasted consistently for two or more years; and these seasonal episodes outnumber other depressive episodes throughout the patient's lifetime.

Common treatment includes light therapy, antidepressent medication, and cognitive-behavioral therapy.

Serotonin and Depression:
Serotonin is a neurotransmitter in the brain, produced from tryptophan hydroxylase and tryptophan (the chemical in turkey that people associate with sleepiness). It helps regulate all sorts of brain functions, including mood, sexual desire, appetite, sleep, memory, temperature, and social behavior. Many people with depression have low amounts of binding sites for which serotonin can bind to, or produce inadequate amounts of serotonin. Serotonin cannot be measured in a living brain, and while it can be measured in white blood cells, this does not necessarily imply a causation of depression, so cannot be used conclusively to prove that serotonin imbalances are directly responsible for depression. Some ways to boost levels of serotonin include a better diet and exercise.
Source: http://www.webmd.com/depression/recognizing-depression-symptoms/serotonin?page=1SSRI blocks the Serotonin from being absorbed by the receptor sites. This stops it from being transmitted into the brain which causes the feeling of happiness and pleasure. This is a cause of depression as explained above.Famous People with Depression:

Marilyn Monroe

Buzz Aldrin

Princess Diana

Vincent Van Gogh

Depression Statistics:Stats
1. Depressive disorders affect approximately 18.8 million American adults or about 9.5% of the U.S. population age 18 and older in a given year. This includes major depressive disorder, dysthymic disorder, and bipolar disorder
2. 15% of the population of most developed countries suffers severe depression
3. 30% of women are depressed. Men's figures were previously thought to be half that of women, but new estimates are higher
4. 80% of depressed people are not currently having any treatment.
5. 15% of depressed people will commit suicide